final report - ARCHIVE: Defra

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Summary of recommendations 15 Research is needed into the development of accurate, cost-effective diagnostic tools for use on live badgers. The absence of such tools is the most important single impediment to progress in various important issues relating to the epidemiology of bTB in badgers, the spatial correlation between bTB in cattle and badgers, and the after-effects of culling. 16 The Independent Scientific Group report claims that cattle measures are sufficient to control TB. We are not convinced of this and are concerned that TB may be self-sustaining in badgers. We therefore recommend investigation of TB in badgers in areas where there are no cattle (or at least no cattle TB) to address this point. 17 The cessation of the badger road-kill study means that the level of TB in badgers outside endemic areas is largely unknown. Some ongoing knowledge of this is important for understanding the role of badgers in the infection cycle, and for identifying new hot-spots. 18 It is imperative that provision be made for continued analysis of data on cattle bTB incidence in and around proactively culled and control RBCT areas, until such time as herd breakdown rates in and around the proactive areas return to baseline levels. A thorough cost–benefit analysis of proactive culling should then be undertaken. 19 It is likely that movement of badgers can be restricted by geographical features. We recommend studies aimed at determining what these features are, how effective they are, and where they map. This would allow smaller and larger areas to be identified that would be effectively isolated, enabling different control measures to be tested or implemented. 20 Genomic sequencing studies should be directed at identifying new variable markers with different rates of change for tracking strains. These would be additional to those markers used in established typing schemes and could provide a much more detailed understanding of transmission routes. 21 The presence of environmental mycobacteria has major implications for diagnosis in cattle, but is also important in human populations in development of disease, and efficacy of vaccination. It would help further understanding of the influence of exposure to these non-tuberculous mycobacteria to describe geographically where there are high levels of relevant species (including Mycobacterium paratuberculosis), for instance through skin test data or through sampling, and to consider whether different control strategies could or should be implemented in different areas based on this. Vaccination 22 There are many questions surrounding the likely efficacy and mechanisms of action of BCG in badgers or cattle. These questions require addressing. The most important of these concerns the impact of exposure to environmental mycobacteria on the efficacy of BCG. However, the results from these studies should not hold back work to vaccinate badgers and cattle and should proceed alongside trials. 23 In the case of badger vaccination, adequate attention should be given to development of optimum bait deployment procedures. 24 A future bTB vaccine which complements or replaces BCG is likely to arise from the programme to devise an improved Mtb vaccine for use in humans. It is clear that Defra scientists have close links 6
Summary of recommendations and collaborate with researchers developing human vaccines against Mtb. There are high-value opportunities for the testing of human candidate vaccines in cattle (or badgers). 25 It seems unlikely that a stand-alone subunit vaccine for use in badgers or cattle will be identified. However, this position should be reviewed if an effective human stand-alone subunit vaccine becomes available. 26 Although the BBSRC programmes do support Defra vaccine work, linkage between BBSRC and Defra projects is not apparent in the documentation available to us. Linkage of all bTB research programmes could be improved. Economic and social 27 Research on economic and social dimensions of bTB was, until recently, limited to assessing the costs of breakdowns and of control measures, with one study looking at public acceptance of control measures involving culling badgers. Farming practices – a critical element in prevention, control and recovery – have been largely ignored as a researchable issue. Current research is exploring a wider set of social and economic impacts of bTB breakdown, and is beginning to assess farmer behaviour from a multidisciplinary perspective (specifically, behaviour in response to movement restrictions). This is a welcome development that should be built on in future studies. 28 If policies are designed to inform and influence farmers’ husbandry practices, an evidence base is needed. This should include studies of farmers’ actual management/husbandry practices following an outbreak on their farm and in the vicinity of their farm, and the sources of advice and information they used (if any) in making changes. 29 This research should also include work to understand farmers’ attitudes towards husbandry practices to reduce risk of badger–cattle contact, and their underlying motivations for changing or not changing their husbandry practices in response to the bTB threat. Management 30 It is likely that successful control will only result from the effective implementation of a combination of approaches. We recommend emphasis on development of a systems approach to the control of bTB in cattle. This means modelling the ways in which different combinations of control measures would interact, and considering the appropriateness of different combinations of control measures to specific areas defined in geographical or disease status terms. We note that in poorly controlled aspects of human infection, such as Clostridium difficile-associated disease, deployment of all measures for which some evidence of efficacy is available has, anecdotally, been associated with improved control. 31 It is likely that control measures will be most effective where they are tailored to specific local circumstances. This requires a significant amount of work in extracting and confirming relevant information from databases and from the locality relating to cattle, badgers, geography and farming practices. This is labour-intensive, but could be partially achieved through imaginative use of resources such as veterinary undergraduate students. 7
Page 1 and 2: The Society for General Microbiolog
Page 3: The Society for General Microbiolog
Page 6 and 7: 4.5 Environmental reservoirs of Mb
Page 8 and 9: Summary of recommendations Finally,
Page 13 and 14: 1 INTRODUCTION Bovine tuberculosis
Page 15 and 16: 2 DIAGNOSIS 2.1 Current and recent
Page 17 and 18: Diagnosis 2.3.2 Conventional micros
Page 19 and 20: Diagnosis 2.5 Strain definition in
Page 21: Diagnosis of bTB. If test results f
Page 24 and 25: Pathogenesis 2008. Consideration of
Page 26 and 27: Pathogenesis where the expression o
Page 28 and 29: Pathogenesis different mycobacteria
Page 31 and 32: 4 ENVIRONMENT AND EPIDEMIOLOGY 4.1
Page 33 and 34: Environment and epidemiology provid
Page 35 and 36: Environment and epidemiology the po
Page 37 and 38: Environment and epidemiology Transm
Page 39 and 40: Environment and epidemiology Transm
Page 41 and 42: 5 VACCINES 5.1 Current and recent r
Page 43 and 44: Vaccines 5.2 Evidence that vaccines
Page 45 and 46: Vaccines based on attenuated Mtb, b
Page 47 and 48: Vaccines investigate adjuvants for
Page 49 and 50: 6 ECONOMIC, SOCIAL AND BEHAVIOURAL
Page 51 and 52: Economic, social and behavioural co
Page 53: Economic, social and behavioural co
Page 56 and 57: Management tools data implicates a
Page 58 and 59: Management tools that (a) reactive
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Management tools 7.6.3 An additiona
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8 REFERENCES Alonso-Hearn, M., Pate
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References Ernst, J. D., Trevejo-Nu
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References Varley, S. & other autho
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References of fertility control and
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Research projects funded by Defra c
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Appendix 1 Documents made available
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Appendix 2 SGM SNP TB TNF TraSH TST
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Appendix 3 Keeping members informe
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final report - ARCHIVE: Defra

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